Renal histomorphometry and resistance index in children with renal disease

Purpose. The aim of this study was to examine the relationships between the renal resistance index (RI) and histomorphometric variables measured in ch ildren with glomerular or nonglomerular renal disease. Patients and Methods. The medical records, sonography reports, and biopsy s pecimens of 30 children with glomerular or nonglomerular renal disease (mea n age, 11.0 +/- 4.7 years; range, 2.5-17 years) who underwent sonographic e valuation and biopsy of the right kidney were retrospectively studied. Biop sy specimens were evaluated for glomerular surface density, number of glome ruli in the stroma, capillary surface density, number of capillaries within the glomeruli, and the diameters of the afferent arterioles. Results. The RI was negatively correlated with age in patients 2.5-4.0 year s old (rho = -1.0, p < 0.001). The RI was positively correlated with serum creatinine levels (rho = 0.63, p < 0.001), and the RI differed significantl y between patients with abnormally high and age-appropriate serum creatinin e levels (0.8 +/- 0.1 and 0.6 +/- 0.1, respectively; p = 0.002). No differe nces in age, histomorphometric variables, RI, or arteriolar diameter were f ound between patients who had interstitial fibrosis and those who did not, and the RI was not correlated with histomorphometric variables in either gr oup. However, the mean RI was significantly higher in patients with severe fibrosis than in those with mild fibrosis. In those with severe fibrosis, t he RI was negatively correlated with number of glomeruli in the stroma (rho = -0.975, p < 0.01), glomerular surface density (rho = -0.931, p < 0.05), number of capillaries within the glomeruli (rho = -0.989, p < 0.01), and ar teriolar diameter (rho = -1.00, p < 0.01). Conclusions. The RI was correlated with histomorphometric variables in pati ents with severe interstitial fibrosis and could be useful in the follow-up of these patients. (C) 2000 John Wiley & Sons, Inc.